To study the shear characteristics of the soil reinforced with herb roots,annual plant Achnatherum splendens roots were adopted as the web of the reinforced soil,and which were planted on the slopes of the test area.The reinforced soil of the roots was divided into nine groups of remolding proof samples according to different root amounts.The shear friction test on the samples showed that:under certain root amount and moisture content,apositive linear relationship was showed between the shear strength of the reinforced soil of roots and the normal pressure of the shear plane,as shear strength increased with the increasing vertical pressure.While under certain moisture content and vertical pressure,shear strength increased with the increasing root amount,cohesion c and internal friction angleφincreased as well,and an exponential relation was showed between cohesion c and root amount,but no significant changes occurred to internal friction angleφ. Exponential relationships were showed between the shear strength of the reinforced soil of the roots and root amount,when the vertical pressure was 20.5,61.5,102.5and 143.5kPa.This study showed that roots of Achnatherum splendens can improve the shear strength in the testing areas and enhance the slope stability.